


Lab Safety Procedures

by thechosentwo



Category: Back to the Future (Movies)
Genre: Fluff and Smut, M/M, Mildly Dubious Consent, Plot What Plot/Porn Without Plot, Sex Pollen, Trans Male Character, ftm!Marty
Language: English
Status: Completed
Published: 2020-08-08
Updated: 2020-08-08
Packaged: 2021-03-06 06:08:14
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,382
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25778674
Author URL: https://archiveofourown.org/users/thechosentwo/pseuds/thechosentwo
Summary: After an accident in the lab, Marty and Doc have to deal with the consequences of Doc's latest experiment. It's pwp don't take it too seriously.
Relationships: Emmett "Doc" Brown/Marty McFly
Comments: 3
Kudos: 45





	Lab Safety Procedures

“Uh, Doc, what the hell was that exactly?” Marty tugged at his collar, suddenly burning up.

Doc’s expression wasn’t reassuring, nor was the haste with which he grabbed Marty’s hand and drug him outside to the showerhead. Marty spluttered at the ice-cold water suddenly pouring over his head. Great, now his jacket was soaking wet and it would take ages to dry. He took off a couple of his layers and tossed them aside to get them out of the way. His shirt clung uncomfortably to his skin, the sudden friction had his teeth on edge. 

“My apologies, Marty, but I had to act quickly,” Doc said, joining him under the water and rubbing vigorously at the spots that had been splashed by the liquid. “That was a powerful hormonal stimulant that I’m attempting to use to encourage difficult animals to breed in captivity.”

The friction against his chest was getting extremely distracting, and it took a few moments for Doc’s words to sink it. That explained the lizards at least. Marty suddenly found himself enamored by Doc’s hands, still scrubbing at his face. With a sinking realization, he realized that it probably explained the building warmth between his legs too. 

“What, uh, what exactly is something like that gonna do to us? I mean, we’re not lizards right?”

Glancing down below Doc’s waistline surreptitiously, Marty figured he had enough of an answer. He fought the urge to keep staring, or worse, reach out and see exactly what that bulge felt like. Doc grimaced in response and dropped his hands to his sides, turning to try and hide the evidence of their current predicament. 

“I fear it may impact us more severely, Marty,” Doc admitted. “Seeing as humans are much more responsive to hormonal changes and, pardon the turn of phrase, much hornier than your average reptile.” 

Tugging at his shirt collar again, Marty wanted nothing more than to shed it all together and stop the infuriating feeling of the wet fabric rubbing against his nipples, which were now hard and sensitive. He was four buttons down when he realized what he was doing and gripped the fabric together in a panic. Doc was still talking. 

“It may affect me especially since there’s already… well..” He trailed off and glanced over his shoulder at Marty. 

Seeing that Marty was halfway through removing his shirt, Doc averted his gaze again quickly. His voice was strained, and his hands were clenched into fists. “You should probably go home, Marty. It will wear off faster if you’re not around anyone and can… handle the problem appropriately.”

A lot of good that would do. All the fantasies Marty had entertained over the past few years came rushing back when he considered it. Ever since they’d gotten back from 1885 something had changed between them. Whether it was influenced by Marty’s second puberty hormones or just the sheer amount of shared experience, Marty’s thoughts had a hard time not straying back to Doc when he was getting off lately. Not that it mattered. Emmett would never return feelings like that, and even if he did, risking their friendship by asking was the last thing Marty wanted to do. 

However, in the current circumstances, considering all the options couldn’t exactly be avoided. Watching the water run over Doc’s body, Marty’s jaw dropped and it was all he could do to keep from panting at the mental image of Doc between his legs, rutting like an animal in heat. He should go. Emmett was right. If he stayed he wouldn’t be able to avoid asking, and regardless of what happened today, he wasn’t sure he wanted to hear what the answer would be tomorrow. 

Another surge of heat flooded his body and he gasped, taking an involuntary step closer to Emmett. Doc looked over at him in alarm. The last few measures of self-control he had were draining out of him. Marty had always been impulsive. 

“I don’t know if I can go,” Marty said, letting go of his shirt and reaching out to put a hand on Doc’s back. 

Emmett shivered at the contact and cursed himself for letting this happen. Lab safety procedures existed for a reason, and he’d been careless one too many times. His pants were too tight and itchy. Nothing was worse on the skin than wet denim. He tried to focus on that discomfort and not on the fact that Marty was standing behind him, half undressed and probably feeling as desperate for touch as he was. How often had he dreamed of this, only for the opportunity to arrive in the worst way possible. There was no way he could impose himself on his friend like this because of a reckless mistake. 

A wet slap against the ground alerted Emmett that Marty had committed to losing his shirt. He turned and grabbed Marty by his now bare shoulders, eyes wild. He had to get through to Marty now before his own willpower fell apart, “Marty, listen to me, we are highly evolved creatures with well-developed brains used for a variety of activities besides breeding. We don’t need to give into this.”

“Sure, Doc, but I’m pretty sure most of my ‘highly developed brain’ is telling me to have sex with you right now,” Marty said, leaning into Doc’s touch, wishing his hands were somewhere else. 

Everything inside of Marty wanted to kiss Dr. Emmett Brown. And why not? They’d been best friends for years; they’d nearly destroyed the time stream continuum together. There was no one Marty could want to be with more than Doc. The past three years of lovesick pining and shame could all be worth it if Doc just kissed him now. Whatever they felt about it when this urge was gone would be fine if he could just find out what it felt like right now to have Doc inside of him. He stepped back out of the water, the cool breeze on his skin making his hair stand on end. Just a little longer and he could know. 

“I’m gonna go inside,” Marty said, holding himself back from trying to undress Emmett right there in the backyard. “I’ll be there if you wanna join me.”

Surely he could distract himself long enough for Doc to come to his senses and realize that he might want Marty too. If he never did… well at least Marty could blame his proposition on hormones and Doc would probably forgive him. Finding it frighteningly easy to shake off his worries, he stripped out of the rest of his clothes and savored the feeling of Emmett’s eyes on him as he walked back inside the garage. Marty sprawled out on Doc’s bed, kicking the mess of sheets down to the end. Using his fingers he tried to relieve some of the aching between his legs.  
__________________________________________________________________________________________  
This was not a decision Emmett was prepared to make. Emptiness threatened to swallow him, and his pants were still uncomfortable. He’d worked so hard over the past few years to make sure they never entered a situation where he would have to make the choice in front of him. After his near slip-up in 1885 when they’d shared a bed and Marty had asked if he was in love with Clara Clayton, he swore he’d never let himself touch Marty like he wanted to. Their friendship mattered too much to him to risk it for something so selfish.

Only now, failure seemed like the only option remaining. He had no idea what Marty was doing inside the garage, but if it was anything like Emmett was imagining he would be done for in mere seconds. Impulse control had never been his strong suit. He turned the water off and removed his own shirt and pants, sighing in relief when he had finally unstuck himself from the soaked denim. He was so hard it hurt. 

Thinking about it seriously: they were both adults. They could still choose whether they wanted this or not. Impaired perhaps, but not without autonomy. Marty had made his choice. And right in front of Doc was a chance to indulge in his desires with minimal consequence. Emmett couldn’t bring himself to believe that they wouldn’t be able to discuss this after it had passed and remain friends. As long as he didn’t let slip that this had been on his mind, as long as they could both pretend it just the result of his fuck up, they could probably be okay afterward. Marty might forgive him yet. He went inside the garage. 

The sight that greeted him when he entered hit like a train. Marty’s face was flushed, water glistening on his face and body, legs spread to offer Emmett a full view. He dragged his eyes upward only to meet Marty’s across the room. Distantly, he realized he was panting. Marty grinned at him, his face growing closer and closer until Doc was sitting on the foot of the bed reaching for him. They were choosing this. 

Nothing prepared Marty for the catharsis of finally having Emmett’s hands on his body. Even just resting on his thighs, the sheer relief made him whimper. “May I?” Doc asked him, almost reverent. 

Marty nodded, not trusting himself to speak. Doc lowered his face and licked up Marty’s slit in one long stroke, tasting him, and then covered Marty’s clit with his mouth. Marty’s hips bucked and the suddenness of it was bordering on painful. He hadn’t fooled around with anyone since starting hormones, so while he knew his bottom growth would be more sensitive he hadn’t realized it would feel like this. He pulled away instinctively, the intense pressure overwhelming his nerves. 

“Are you alright?” Emmett’s voice was husky and low, his eyes unfocused. 

“Yeah, great, Doc,” Marty gasped. “Just not so hard, yeah?”

Doc hummed in response and returned to his ministrations with a much more gentle touch. Marty’s eyes fluttered shut and he reached out for anything to grab onto. He felt untethered; the only point of contact left was between his body and Doc’s tongue. The waves crashing through him were like a fever. He wondered if it would burn them out before the night was through. 

“Enough, that’s enough, Doc,” he gasped out. “Need you. Now.”

Unsure if Doc had heard him, he was about to repeat himself when a kiss shut him up. An honest to god kiss. This took his breath away more than anything had yet. As much as he needed the physical satisfaction, he’d been craving this above all else. Doc’s face was rough, stubble already starting to come back in from his shave that morning. Marty could taste himself in Emmett’s mouth, their tongues exploring each other. Marty didn’t think he’d ever get to have this. 

Higher functioning seemed to be entirely shut off in Emmett’s brain. He could only focus on Marty, on Marty’s body, his lips and breasts, his hips. Deciding to keep his eyes open during their kiss, he admired Marty’s eyelashes and the few scattered freckles hidden across his face. Doc had been starving for years and the feast in front of him was almost too rich to trust. He grabbed Marty’s thighs and lifted them, angling their hips so he could sink into Marty slow and easy.

Whispers in the back of his selfishly hoped this was Marty’s first time, that he would get to make Marty his more completely than anyone else. The possessiveness may have surprised him any other time, but now he just let it boil. Marty was here begging him for it. He groaned, shifting inside Marty, the muscles contracting around him. This was how they were meant to be. Marty cried out under him. He set a steadying hand beside Marty’s head and set a steady pace against Marty’s hips rising to meet him. 

More than pleasure, Marty felt contentment radiating out from his core. It was a cool breeze over the feverish heat. This was how they were supposed to be together. He felt complete. He leveraged up as hard as he could, desperately trying to get Doc deeper inside of him. The heat broke and he shouted, clenching around Doc, every nerve alight. The pleasure faded but the electricity didn’t, and after a few brief moments of nausea the pleasure started building again and Marty melted into the contact.

“Marty,” Doc’s voice was tinged with desperation, ragged and breathless. “Marty, I..”

Emmett cut himself off with a gasp as he climaxed, balls tightening and releasing. His arms shook from the effort of remaining upright. Marty whined under him, squeezing Doc as close as possible with his legs. The spreading warmth hit the emptiness Marty had been trying to fill, and he was starving for it. He wanted all of it. Panic sparked when Doc started to pull out and he tightened his grip. Not yet. It couldn’t be over yet. 

Lowering himself to his elbows, Emmett brushed a strand of hair out of Marty’s face. He tried to steady his breathing. The feverish heat had drained out of him and all that remained was a pleasant, fond glow. He kissed Marty’s nose gently and eased himself out when Marty’s legs relaxed. Doc pulled Marty close to his chest and curled around him protectively. Maybe the regret would set in soon, but he intended to savor every last second he got. 

Marty opened one eye and squinted at him, grimacing. The peace he felt overruled any anxiety he would have normally had about what he wanted to say. “Doc, would you hate me if I said I wanted you without your crazy hormones?”

The shock he saw wasn’t unexpected, but it wasn’t encouraging either. Just as Marty was about to take it all back as a joke, Emmett kissed him. No desperation, no residual lust. Just the two of them. “I would never hate you, Marty. In this case, I’d have to say I felt the same. Denying it hasn’t done me any good, so what the hell?”

“Heavy,” Marty said, then laughed and pressed against him, exhaustion setting in.

They had all the time in the world to talk. For now, he just wanted to lay there and be in love.

**Author's Note:**

> posting this before I get too self-conscious about 
> 
> It's been ages since I wrote genuine smut so have fun lol
> 
> filler content until I get the new amplified chapter up


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